there are three exams in a marking period. A student received grades of 75 and 81 on the first two exams. What grade must the students earn

Question

there are three exams in a marking period. A student received grades of 75 and 81 on the first two exams. What grade must the students earn on the last to get an average of no less than 80 for the marking period?

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Ngọc Khuê 3 years 2021-08-06T16:51:42+00:00 1 Answers 53 views 0

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  1. taiduc
    0
    2021-08-06T16:52:48+00:00
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    Answer: average means add all scores and divide by number of scores earned


    last score is x

    so the sum is 75+81+x

    3 scores so (75+81+x)/3=average

    must be no less than (greater than or equal to 80)

    (75+81+x)/3≥80

    solve


    times both sides by 3 to clear fraction

    75+81+x≥240

    156+x≥240

    minus 156 from both sides

    x≥84


    the studen must earn at least 84 on last exam

    Step-by-step explanation:

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